Various electronic devices (avionics devices) exclusively for aircraft are incorporated into the aircraft to implement functions of gauge display, communication, navigation, flight management, etc., of the aircraft. The avionics devices are provided in respective parts of a fuselage. The avionics devices are connected to various terminal devices associated with gauge display, communication, navigation, flight management, etc., and are interconnected to construct one system (hereinafter referred to as “electronic system mounted on an aircraft”). The avionics devices are configured as LRUs (line replaceable units) so that they can be replaced promptly if a failure is found out in these avionics devices in maintenance.
In recent years, the aircraft is required to achieve weight saving of the fuselage (fuselage weight saving) to achieve higher fuel efficiency, or the fuselage or incorporated devices are required to be more simplified (configuration is more simplified) to provide maintenance of the fuselage at lower cost. However, in actuality, there is a room for improvement in achievement of the fuselage weight saving and achievement of simplified configuration.
To be specific, for the aircraft, development has been made to provide higher functions in gauge display, communication, navigation, flight management, etc. In addition to these functions, development has been made to provide another multiple functions. Because of this, electronic devices other than the avionics devices have been increasing in number, and wires connecting these electronic devices have been increasing in number. With an increase in the electronic devices and the wires, the weight of the fuselage increases, which precludes the fuselage weight saving. With an increase in the kinds of the electronic devices, simplification of the configuration is precluded, and auxiliary components of the electronic devices increase in number, which increases cost. Furthermore, with an increase in the electronic devices and the wires, a space occupied by these electronic devices and the wires increases, but a passenger space and a cargo space are narrowed, which will result in a reduced transportation efficiency.
As a solution to the above, recently, regarding the avionics devices, IMA (integrated modular avionics) units have been used in many cases. The IMA unit is configured such that plural kinds of avionics devices are integrated together. In an exemplary IMA unit, a plurality of functional modules are mounted in a single casing such that they are replaceable. In this configuration, a power supply, a CPU, an interface and the like, which are common to the avionics devices, are provided as common modules, and components unique to the functions are provided separately. This allows functions of many avionics devices to be substantially integrated into one IMA unit. As a result, the weight of the electronic system mounted on the aircraft and its occupied space can be reduced. In addition, the auxiliary components of the electronic devices can be reduced in number.
Among various aircrafts, in large-sized passenger aircrafts (hereinafter referred to as large-sized aircrafts), control systems of functions of the fuselage are integrated, separately from systems associated with gauge display, communication, navigation, flight management, etc. As such control systems, there are a landing gear system for moving up and down wheels, a fuel system for controlling a fuel, etc. In these control systems, terminal devices such as sensors, actuators, and other devices which are provided in respective parts of the fuselage, are connected to the electronic devices, to construct electronic systems mounted on the aircraft for respective functions.
For easier explanation, systems associated with gauge display, communication, navigation, flight management, etc., are referred to as “avionics system,” and control systems of functions of the fuselage, which are other than the avionics systems, are referred to as “utility systems.” Since the avionics systems have substantially the same functions for various fuselages, a common system of the avionics systems can be easily implemented. Therefore, avionics manufactures are developing the IMA units for the avionics systems. However, it is difficult to construct a common system of the utility systems because components in the utility systems are unique to the fuselage. Under the circumstances, LRUs have been developed for the utility systems, but integration thereof has not been developed.
To be specific, as shown in a schematic control block diagram of FIG. 7, for example, the utility systems of the aircraft include a landing gear system 61, a fuel system 62, a flame detection system 63, a breed air system 64, a de-icing system 65, and others, each of which includes terminal devices (The terminal devices will be described in detail in the description of the embodiments later). Among these systems, the landing gear system 61 is controlled by a landing gear controller 71, the fuel system 62 is controlled by a fuel controller 72, the flame detection system 63 is controlled by a flame detection controller 73, the breed air system 64 is controlled by a breed air controller 74, and the de-icing system 65 is controlled by a de-icing controller 75. The landing gear controller 71, the fuel controller 72, the flame detection controller 73, the breed air controller 74, and the de-icing controller 75 are constructed as LRUs.
As schematically shown in FIG. 8A, in a conventional aircraft 101, in the utility systems, many LRUs 70 such as the above stated controllers are mounted in a fuselage 81, and are connected to terminal devices (not shown) via many wires 60. In this configuration, the LRUs 70 and the wires 60 are laid out in an unadjusted manner according to functions of the aircraft 101.
When the IMA unit is used in the utility system, as shown in FIG. 8B, for example, in an aircraft 102, two IMA units 50 are laid out in a nose part of a fuselage 82 and many wires 60 extend from the IMA units 50 to terminal devices (not shown) provided in respective parts of the fuselage 82. This can reduce the weight of the electronic components, the space occupied by the electronic components and the number of auxiliary components, in the utility systems too. The reason why the two IMA units are provided in the nose part is to construct a double redundant system.
As can be clearly seen from comparison between FIGS. 8A and 8B, the amount of the wires 60 cannot be reduced sufficiently when the IMA units 50 are merely used. Therefore, for the large-sized aircraft, a technique is known, in which the avionics systems and the utility systems are integrated by using the IMA units and data buses are used.
In a specific example, although not shown, for example, two IMA units are laid out in the nose part, a plurality of remote data concentrators (RDCs) are provided in required locations of the fuselage, a plurality of wires extend from the RDCs to respective parts of the fuselage, and IMA units and the RDCs are connected together by means of data buses.
In this configuration, the respective IMA units are connected to the RDCs by means of the data buses, and data gathered from the respective parts of the fuselage are sent to the IMA units. In accordance with this configuration, by using the RDCs and the data buses, wires having a substantially required length are connected to the RDCs. This can reduce a physical amount of the wires and allows the data gathered from overall fuselage to be processed concentratively in the IMA units. As a result, the overall system can be simplified in configuration.
As an example of a technique which uses the IMA units and the data buses in the electronic system mounted on the aircraft, there is a technique disclosed in Patent Literature 1. This technique addresses a problem associated with ARINC 659 data buses, among data buses for avionics standardized in ARINC. As an example of a technique for integrating the avionics systems with the utility systems, there is a technique disclosed in Patent Literature 2.